Lift/Drag Prediction of 3-Dimensional WIG Moving Above Free Surface

  • Published : 2001.03.01

Abstract

The aerodynamic effects of a 3-dimensional Wing in Ground Effect (WIG) which moves above the free surface has been numerically investigated via finite difference techniques. The air flow field around a WIG is analyzed by a Marker & Cell (MAC) based method, and the interactions between WIG and the free surface are studied by the pressure distributions on the free surface. Waves are generated by the surface pressure distribution, and a Navier-Stokes solver has been employed, to include the nonlinearities in the free surface conditions. The pressure values Cp and lift/drag ratio are reviewed by changing the height/chord ratio. In the present computations a NACA0012 airfoil with a span/chord ratio of 3.0 are treated. Through computational results, it is confirmed that the free surface can be treated as a rigid wavy wall.

Keywords

References

  1. Abbott, I. H. and Von Doenhoff, A. E., 1958, 'Theory of Wing Sections,' Dover Publication, New York
  2. Hirata, N., 1993, 'Simulation on Viscous Flow around Two Dimensional Power Augmented Ram Wing in Ground Effect,' Jour. Soc. Naval Arch. of Japan, Vol. 174, pp. 47-54
  3. Lippisch, A. M., 1964, 'The Aerodynamic Grounded Effect and Development of the Aerofoil Boat,' Luftfahrtechnik Raumfahrteknik, 10, pp. 261-269
  4. Lockheed California Company Report, 1962, 'Preliminary Economic Analysis of Winged Hull Vehicles,' LA/ME/2148
  5. Lungu, A. and Mori, K., 1994, ,'Developments of the Finite Difference Schemes for Free-Surface Flow Computation,' Proc. Int. Workshop on CFD., Tokyo, Vol. 1, pp. 331-340
  6. Masuda, K. and Suzuki, K., 1991, 'Simulation of Hydrodynamic Effects of 2-Dimensional WIG Moving Near the Free Surface,' Jour. of Soc. of Naval Arch of Japan, Vol. 170, pp. 83-92
  7. Riegels, F. W., 1961, 'Aerofoil Section,' Butter Worths, London
  8. Smithey, W. J. H., Papadales, B. S. Jr. and Chaplin, H. R., 1977, 'Effect of Turbulent Jet Mixing on the Static Lift Performance of a Power Augmented Ram Wing,' David Taylor Naval Ship Research and Development Centre ASED-389